Various computer peripheral devices have been developed in response to the progress of computer information industry. In order to facilitate data sharing and transmission between computer information products, the peripheral devices such as CD-ROM driver, printer, scanner, mobile storage device and so on are externally connected to computers by means of connectors having common connecting interface consistent with Universal Serial Bus (USB) specification or IEEE (Institute of Electrical and Electronics Engineers) 1394 specification, etc. The USB connecting interface has become the important connecting interface for the peripheral devices because it has a much higher transmission rate than that of parallel ports or serial ports of a personal computer and also provides a plug-and-play function for the computer platform. Similarly, the IEEE 1394 connecting interface also has a fast transmission rate at least up to 200 Mb/S and the plug-and-play function.
As there is a need to store more and more data in the form of music and picture files, conventional data storage devices are no longer suitable as not having sufficient data storage capacity. Accordingly, a portable electronic device such as a flash memory hard disk provided with a USB connector serving as data transmission interface, or so-called USB storage device, is proposed. The USB storage device has large data storage capacity, high transmission rate, good portability and low cost and is thus widely used.
Since the USB storage device is connected via a connection portion thereof (i.e. the USB connector) to an external device such as a computer to perform data transmission, if the USB connector is damaged due to external force or impact, the performance of the USB storage device would be adversely affected. Conventional USB storage device utilizes a protective cover to protect the USB connector. As shown in FIG. 1, the protective cover 52 is provided to cover the connection portion 511 of the conventional USB storage device 51 when the USB storage device 51 is not in use. However, during the practical application, as the protective cover 52 must be removed in order to use the USB storage device 51, the protective cover 52 is easily lost, making the connection portion 511 fail to be protected and thereby reducing the lifetime of the USB storage device 51.
Therefore, the problem to be solved here is to provide an electronic device itself having a sheath structure, without having to use a detachable protective cover to protect a connection portion of the electronic device.